To determine the corrosion current density of the copper plate in the 0.1 M NaCl solution, we need to use the Tafel equation. The Tafel equation relates the corrosion potential E_corr , the Tafel slope b , and the corrosion current density i_corr as follows:E = E_corr - b * log10 i_corr / i Where:E = corrosion potential -0.54 V vs. SHE E_corr = equilibrium potential of the copper plateb = Tafel slope 120 mV/decade = 0.12 V/decade i_corr = corrosion current density A/m i = exchange current density A/m First, we need to find the equilibrium potential E_corr of the copper plate in the 0.1 M NaCl solution. The standard reduction potential for copper Cu/Cu is +0.34 V vs. SHE. Since the corrosion potential of the copper plate in the solution is -0.54 V vs. SHE, the equilibrium potential E_corr is:E_corr = E - -0.54 V = 0.34 V + 0.54 V = 0.88 VNow, we can rearrange the Tafel equation to solve for the corrosion current density i_corr :i_corr = i * 10^ E - E_corr / b We don't have the value for the exchange current density i for the copper plate in the 0.1 M NaCl solution. However, we can estimate it using typical values for copper in similar environments. A common value for i for copper in chloride solutions is around 10^-6 A/m.i 10^-6 A/mNow, we can plug in the values into the equation:i_corr = 10^-6 A/m * 10^ -0.54 V - 0.88 V / 0.12 V/decade i_corr = 10^-6 A/m * 10^-1.42 V / 0.12 V/decade i_corr = 10^-6 A/m * 10^-11.83 i_corr 1.47 * 10^-18 A/mThe corrosion current density of the copper plate in the 0.1 M NaCl solution at 25C is approximately 1.47 * 10^-18 A/m.